The present invention relates to a bottle-filling machine. More particularly this invention concerns a conveyor for a bottle-filling machine and a method of loading bottles onto and removing them from the conveyor.
A bottling apparatus as described in U.S. Pat. No. 6,343,628 has a frame and an endless conveyor element on the frame, having a horizontal working stretch extending in a transport direction through a filling station, and carrying a plurality of holder plates each formed with a row of seats adapted to fit snugly around necks of bottles. Couplings releasably secure the holder plates to the conveyor element with the holder plates spaced in the transport direction along the working stretch and the rows extending transverse to the transport direction. Bottles are loaded into the seats upstream of the filling station with mouths of the bottles open upward and the bottles hanging by their necks from the holder plates and are removed from the seats downstream of the filling station. A drive advances the conveyor element stepwise in the transport direction in the working stretch and arrests each of the holder plates in the filling station with the bottles in its seats aligned with the fill tubes. A plurality of stationary upright fill tubes in the filling station above the working stretch are aligned with the seats of the holder plate in the filling station. The plates are lifted in the filling station off the conveyor element to engage the fill tubes down into the respective bottles so they can be filled through the tubes.
Upstream of the filling station the bottles are cleaned and sterilized and downstream of the filling station they are fitted with caps and sealed. This system is particularly useful in filling the bottles with liquids and semiliquids such as yoghurt.
Thus with this system the bottles are held by their necks and are raised by the holders up to insert the fill tubes into them. In this manner it is possible even to align a relatively small bottle mouth perfectly with a filler tube and fill a relatively large bottle with liquid while generating no foam. The holders are lowered synchronously as liquid is introduced into the bottles to keep the liquid level at a constant position relative to the filler tubes. Such an arrangement can work with tall or short bottles easily with the same holder plates.
The conveyor element has in the working stretch an upper surface and the plates have in the working stretches lower surfaces resting on the conveyor element upper surface. The couplings each have according to the invention a vertically extending pin projecting from one of the surfaces and a coupling hole in the other of the surfaces receiving the respective pin. More particularly the pins project and taper upward from the upper conveyor-element surface and the coupling holes are formed in the plates. In addition the conveyor element is formed by a pair of horizontally spaced endless chains each having a succession of the pins. The plates are each transversely elongated and have ends each formed with a respective one of the coupling holes.
Each plate in this system is formed by a pair of separable subplates each formed with a pair of transversely spaced coupling holes. Confronting edges of the subplates have cutouts together forming the seats, and the subplates are pivoted apart at upstream and downstream ends of the working stretch to allow bottles to be loaded in and taken out.
While this arrangement is relatively effective, it still could use some improvement with respect to the loading of the bottles into the seats and taking them out. This is normally done when the seats are just barely open wide enough to allow the bottles to be fitted in and out, requiring the bottles to be moved with great precision. In addition the bottles must be tipped during the loading and unloading, so that an imperfectly closed bottle will spill.
It is therefore an object of the present invention to provide an improved bottle conveyor.
Another object is the provision of such an improved bottle conveyor which overcomes the above-given disadvantages, that is which allows bottles to be loaded onto and unloaded from it with relative ease.
A further object is to provide an improved method for loading a bottle into and taking a bottle out of a standard plate-type conveyor.
A bottle conveyor system has according to the invention a chain having a horizontal stretch extending in a transport direction and carrying lower pins spaced apart in the direction and extending upward in the stretch. A drive displaces the chain in steps through a station and stops the chain in the station. Respective pairs of plates have vertically throughgoing holes each fitted to a respective one of the pins and confronting cutouts together forming seats shaped to fit complementarily around necks of bottles. A pair of supports in the station above the chain have respective downwardly projecting upper pins movable generally in the transport direction between a transfer position aligned with respective lower pins of the chain stopped in the station and a spread position. An actuator can raise the plates in the station in the transfer position of the upper pins and thereby slide the holes of the plates in the station from the lower pins onto the upper pins. The arms and upper pins are moved apart into the spread position when the plates are on the upper pins to open up the seat so that a bottle can be fitted to or taken out of the seat when it is thus opened up. The arms and upper pins are moved together into the transfer position when the plates are on the upper pins to close the cutouts around a bottle positioned between them.
Thus with this system it is possible to spread the plates relatively far apart, while still maintaining them under perfect control, so that a bottle can be brought down into position between them or, if the system is used for unloading the conveyor, for moving it out from between them. The system is particularly advantages for polyethylene bottles having an upper small neck region and a relatively fat body, as it allows the wide body part to be moved easily between the carrier plates, either upward or downward. Such bottles can be fed in from above and moved up out of-the conveyor, something that was very difficult or impossible when they had to be loaded in and taken out where the chains move around the end sprockets.
The bottle conveyor system further has according to the invention means for moving a bottle having a neck between a position with the neck aligned with the plates when raised and a position offset vertically therefrom. This bottle mover engages only a bottom surface of the bottle.
The upper pins in accordance with the invention have downwardly tapered lower ends and the lower pins have upwardly tapered upper ends. The pin ends are substantially identically frustoconically tapered. In addition the pins are substantially identically cylindrical except at their ends.
The method of this invention therefore comprises the steps of positioning the plates on the lower pins with the cutouts confronting each other and forming seats and displacing the chain in steps through the station and stopping the chain in the station with the lower pins aligned underneath the upper pins in the transfer position of the upper pins. The plates in the station are raised in the transfer position of the upper pins to slide the holes of the plates in the station from the lower pins onto the upper pins without changing the relative horizontal position of the plates. Then the arms and upper pins are spread with the plates apart into the spread position when the plates are on the upper pins to open up the seat formed by the plates on the upper pins, whereupon a bottle can be fitted to the opened-up seat. Finally the arms and upper pins are closed together into the transfer position with the plates are on the upper pins to close the cutouts around the bottle positioned between them. The plates are then dropped back down to the conveyor for transport away through the sterilizing, filling, capping, and sealing stations. In an end unloading stations these steps are reversed to take the full, capped, and sealed bottle off the conveyor.
The supports and upper pins are displaced symmetrically apart in the station. In addition the supports and upper pins are displaced apart and together parallel to the transport direction.